Molar heat capacity of GeTe, SnTe, and PbTe from 0.9 to 60 K

The molar hat capacity of GeTe, SnTe, and Pbte have been measured by the heat-pulse method from 0.9 to 60 K. No conclusive evidence was found for th effect o the soft TO phonon modes known to be presen in these mateials. An anomalous excess heat capacity previously reported near 3 K for GeTe was not confirmed. A deailed comparison of the calorimetrc ΘD(T) and that calculated from the phonon despesion curves as measured by inelastc netron scatteing has been made for SnTe and PbTe, with the result that the lattice dynamical model for PbTe has been virified but a minor refinement is indicated for SnTe. An attempt to explain an anomalous heat capacity for PbTe near 2 K based on the soft TO modes was unsuccessful and the effect remains unexplained. No superconductivty was found in PbTe above 0.9 K.